1. Field of the Invention
The present invention relates generally to internal combustion engines and more specifically to a system for monitoring the combustion process which occurs in the combustion chamber or chambers of same and for providing data in close to real time, which can be used to indicate improper ignition timing, misfire and the like and which therefore facilitates improved ignition and/or air-fuel control.
2. Description of the Prior Art
Numerous engine control systems have strived to detect engine vibration (knock) and to adjust the timing of the ignition to the threshold of engine knocking. However, under given circumstances this technique does not lead to the actual MBT timing and thus has tended to lack effective control under all circumstances.
U.S. Pat. No. 4,216,750 issued on Aug. 12, 1980 in the name of Kobayashi discloses an engine control system wherein the combustion pressure and the crank angle are detected and the presence of an engine misfire determined when the maximum combustion pressure occurs essentially at or close to TDC and the presence of proper combustion when the maximum pressure develops later in the expansion stroke. However, this system while being equipped with a pressure sensor via which the maximum combustion pressure necessary for MTB control can be detected, has been incapable of detecting a misfire when the engine is idling.